Traffic Sensors

(Last Updated On: January 13, 2017)

Traffic lights don’t just randomly change; they change because someone wants them to.  These sensors let the intersection lights know that you exist, so make sure you stop in the correct stopping position over the sensor.  If you stop too far forward, or too far behind the sensor, your traffic light might stay Red FOREVER! If this happens, you may need to roll forward or backward just a bit.

See also : How To Tell if the Light will Change to Yellow Soon

Many moons ago, Carmen became an ICBC-approved driving instructor at the age of 22 in North Vancouver, and has spent many years working with new and experienced drivers around the lower mainland. She can be found reading the Motor Vehicle Act for fun while receiving strange looks from others. May the quest for great driving continue!

Related Post

  • competentdrivingbc

    “12th Avenue & Main Street West/Northbound”

    Um, no, I haven’t taken leave of my sensors; I should have said West/Southbound because otherwise you wouldn’t be turning left, eh?

  • Ann

    What type of traffic sensors do we have in Richmond or Vancouver? Are they weight sensors or electromagnetic sensors? Or both?

    • competentdrivingbc

      Responding to Ann’s question, I don’t think that traffic sensors have ever been weight activated; if they’re not magnetic (or other – i.e. sensors that recognise when there’s a bus under them, or an emergency vehicle approaching), then there’s some type of timing system involved; occasionally random though more often timed to a purpose, such as moving traffic efficiently at peak periods – in Coquitlam, they call this the ‘green wave’.

      For instance, back in 1986 with Expo approaching, the City of Vancouver spent $10,000,000 to properly synchronize the lights on one-way arterial roads feeding to and from bridges and viaducts; Dunsmuir/Georgia (the one-way section), Richards/Seymour/Howe, Thurlow/Hornby, Nelson (the one-way section)/Smythe. If you can cruise at 50km/h along any of these, you will make every green light; this is not an accident, it is a design – one which Gregor Robertson doesn’t seem to understand at all as he and his council have chosen to use several of these to create bicycle lanes, for pity’s sake, even though there are adjacent streets that would work much better.

      If you’re driving on a road with traffic lights, and there are no pedestrian push buttons on the corner (or they’re deactivated, such as on Davie) then you’re dealing with some kind of timed system; that’s why on a two-way such as Georgia street downtown, you ain’t never going to get a string of lights in your favour, whether you’re a pedestrian, cyclist, driver, or hanglider; it just can’t be achieved to work for everybody all of the time, regardless of flow or demand.

      These magnetic sensors can be more than on/off switches; they can be programmed to not only sense the presence of vehicles, but the absence of vehicles crossing over them, over a given time period; that’s why very soon after the last oncoming left-turner disappears from the left-turn chute, your solid green to go straight goes on. And those left turn chutes can be set up (as at 12th Avenue & Main Street West/Northbound) so that if there’s only one or two cars waiting to turn left, therefore able to enter the intersection and wait in it after the light has turned green, the sensor won’t activate a ‘green arrow’ phase to enable none-existent left-turner type people. But if there are half a dozen cars backed up in the chute, then it will – clever, eh?

      I don’t get out to Richmond very often, so my information may not be up to date; but I’ve worked there previously doing driver evaluations for their municipal workers, and my general impression is that they still favour ‘timed’ over ‘demand’ systems; but look for those magnetic loops in the roadway, or those pedestrian pushbuttons on the adjacent corners, and you’ll know pretty quickly which is being used; keeping in mind that even ‘demand’ systems may be linked to traffic flow from other lights several blocks away.